Electric pull chain socket



June 25, 1935. J 300 2,006,195

ELECTRIC PULL CHAIN SOCKET Filed Jan. 27, 1931 3 Sheets-Sheet l Q Q Q INVENTOR Harmon J. Cook.

BY H15 ATTORNEY June 25, 1935. H J COOK 2,906,195

ELECTRIC PULL CHAIN SOCKET Filed Jan. 27, 1931 3 Sheets-Sheet 2 INVENTOR Harmon J Cook.

BY HIS ATTORNEY June 25, 1935. H. J. cooK ELECTRIC PULL CHAIN SOCKET Filed Jan. 27, 1931 5 Sheets-Sheet 5 INVENTOR Harmon J. Cook ATTORNEY Patented June 25, 1935 UNITED STATES PATENT OFFICE Application January 27 11 Claims.

This invention relates to electric switches and circuit breakers, and more particularly to an electric pull chain socket switch of the hill and valley type, which will be capable of carrying and interrupting quite heavy loads without danger of injurious arcing or flash-overs.

One object is to provide a pull chain socket switch of the intermittently operated ratchet type, in which the rotary contact carrier will be telescoped within the stationary contact base whenever the switch is in the fully open or fully closed position.

A further object is to provide a pull chain socket switch of the above nature, in which the rotary contact carrier is provided with a pair of downwardly projecting inclin d lugs for supporting the two sides of the rotary contact, said lugs being adapted to snap below the upper surface of the stationary contact base for filling the space surrounding the contacts.

A further object is to provide a pull chain socket switch of the above nature in which any are which may be started by the separation of the contacts will be instantly checked and destroyed by the interposition of an insulating barrier between said contacts which blots out all of the air space, restricts the arc path, and cools the conducting gases.

A further object is to provide a pull chain socket switch of the above nature which will be capable of safely carrying and interrupting a current three to four times as great as was possible with the former air-break type of socket switch using the same size of metal contacts.

A further object is to provide a device of the above nature which will be simple in construction, having only a fraction of the number of parts as compared with the previous standard type of sockets of this general nature.

A further object is to provide a pull chain socket of the above nature which will be inexpensive to manufacture, compact, ornamental in appearance, and very efficient and durable in use.

With these and other objects in view there has been illustrated on the accompanying drawings one form in which the invention may be conveniently embodied in practice.

In the drawings:

Fig. 1 represents a vertical sectional view, partially broken away, of the electric pull chain socket switch.

Fig. 2 is a fragmentary sectional view of the same, taken along the line 22 of Fig. 1, the switch being shown with the circuit closed.

, 1931, Serial No. 511,523

Fig. 3 is a top plan view looking downward upon Fig. 2.

Fig. 4 is a transverse sectional view, taken along the line 4-4 of Fig. 1, looking downwardly.

Fig. 5 is a transverse sectional view taken along the line 5-5 of Fig. 1, looking upwardly.

Fig. 6 is a perspective view in separated relation of the insulating cap, the movable contact carrier, the spring-operated ratchet and associated parts.

Fig. 7 is a top plan view of the rotary contact carrier.

Fig. 8 is a perspective view of one of the stationary contact members which is formed integrally with the center contact of the screw shell socket.

Flg. 9 is a perspective view of the other stationary contact member.

Fig. 10 is a perspective view of one of the pairs of cap-supporting conducting brackets.

Fig. 11 is a bottom view of the insulating base member.

Fig. 12 is a top plan view of the same.

Fig. 13 is a perspective view of the same.

Fig. 14 is a. diagrammatic development view of the cooperating contacts with the rotary contact member shown in on position.

Fig. 15 is a similar view with the rotary contact member advancing to off position.

Fig. 16 is a similar view with the rotary contact in off position.

An arc, as generally understood, consists of a stream of charged particles passing through an open space in the form of a tube or core surrounded by luminous gas. The are continues to carry current as long as the central portion remains hot enough to maintain the flow of charged particles. It can be ruptured and destroyed by stretching it, cooling it, or obstructing it. In the present improved form of pull chain socket, the arc is immediately checked by interposing an insulating cooling barrier between the interrupted contacts, whereby it will be completely smothered and extinguished. The obliteration of the arc is partly due to the fact that the open spaces about the contacts are completely obliterated. Under these conditions, the arc is immediately cooled and choked off and simply cannot exist as there is nothing to support the conducting stream of charged particles forming the arc.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral It] indicates a stationary contact-carrying insulating base member which is substantially cylindrical in shape and preferably formed of porcelain. The base member ID is provided with a central socket II extending downwardly into its upper face He! and within which is mounted the lower end of a cylindrical pin I2 extending upwardly and terminating in an upper square head I3 having a slot I4. By means of this construction the pin may be adjusted whenever desired. The head I3 of the pin I2 is seated within a square socket |3a in an upper insulating cap member I5 also formed of porcelain and having a cylindrical opening I6 at its center for permitting a screw driver to be readily inserted in the slot I4 of the head I3. The head I3 may thus be depressed below the socket |3a and twisted 90 degrees within a cylindrical chamber IBa in either direction for adjusting the tension of a coiled spring 'I'I surrounding the pin I2, V

The coiled spring IT has a vertical upper extremity I8 seated in an aperture I9 in the head I3, the lower extremity of said spring 'II being horizontal and connected with an upstanding lug 28 of a ratchet 2|. The ratchet 2| is adapted to lie in flat contact with the top of a rotary contact carrier 22, preferably formed of a phenol condensation product or other similar insulating material. The ratchet 2| is provided with an enlarged upper inclined radial wing 23 for guiding a switch-operating bead chain 24, the inner extremity of which is detachably locked within a slotted eye 25 depending from one side of said wing 23. T

The bead chain 24 is also guided by the outer circular periphery 24a of the rotary contact carrier 22, from which it passes tangentially at a slight upward incline through a flared tubular outlet bracket 26 having its lower end seated in a slot 26a of the stationary base III.v The bracket 26 passes outwardly through an outer enclosing metallic shell 21 within which isan insulating lining 28, as clearly shown in Figs. 1 and 4. I

The ratchet member 2| is provided with four downwardly inclined lugs 29 adaptedto engage in a similar number of inclined sockets 3fl provided in the top surface of the rotary contact carrier 22, as shown in Fig. 7. The ratchet2| is adapted to index said carrier 22 one quarter of a circumference with each actuation of the pull socket chain 24. i

The spring II'is arrangedto press the rotary contact carrier 22 downwardly upon the-stations ary base member ID at all times'and is :also adapted to return said carrier to its initialposition after each operation of the switch. The rotary contact carrier 22' is provided onits under face with a central socket 3| partially enclosed by a pair of curved opposed ribs 22a'for receiving the central portion of the contact member 36 and adapted to fit over an annular boss 32 in the stationary base In surrounding the socket II. The socket 3| has a central aperture '33 .for permitting said carrier 22 to rotate freely and slide up and down upon the pin I2. The ribs 22a serve as additional barriers to prevent arcing between the central portion of said rotary contact 36 and the stationary contacts 43 and 44;

Extending downwardly from the rotary carrier 22 are a pair of curved inclined lugs 31 and 35 which are adapted to form supports for a twopart integral contact member 35 having inclined outer extremities 31 and 38 adapted to lie loosely in engagement with the inclined lugs 34 and 35. The contact member 36 is provided with a pair of upturned lugs 38a for fitting into slots 3812 at the base of the lugs 34 and 35, whereby said movable contact member as will be caused to move with said rotary carrier 22. Surrounding the boss is an annular depressed socket Illa having its base provided with a plurality of raised inclined serrations, similar to a face ratchet, and providing four connected abrupt shoulders it and cam sections ll and 12. The lugs 3i and 35 have abrupt shoulders 39 at their outer extremities which are adapted to abut tightly against similar abrupt shoulders 4c of the {four equally spaced serrations described above,

when the switch is in the on and oil positions;

. The two opposed inclined sections 4| are left blank so as to form insulating seats for the movable contact extremities switch is in the oil position, while the other two inclined sections it? are provided with inclined stationary contacts 63 and M for engaging the extremities of the movable contact 36 when the switch is in the on position. By means of this construction, it will be seen that positive insulating barriers are interposed between and around each set of movable and stationary contacts, eliminating all air space which might support an arc and instantly cooling and breaking any arcs which may initially form at the interruption of the circuit.

The contact 43 leads directly to one of the line conductors through an angular supporting bracket 45 connected to the base I l as by a screw 45 and having a lateral binding post in located near the upper end thereof. The bracket A5 is also provided at its top with a horizontal eye lug 68 for receiving a screw 69 extending down through the upper insulating cap I5. The bracket 4'5 has a base 5i] provided with a tapped hole 5| to receive a screw which passes through a lateral aperture fill) cf the stationary contact 43, thus securely fastening said contact 43 and bracket 45 to the base iii.

A similar supporting bracket member 52 is connected at its lower end to a screw shell 52a by means oi a conducting screw 53, and has an upper eye lug 5 3 similar to the eye lug it for receiving a screw 55 for connection with the base Ill. The bracket 52 also has a binding post 56 similar to the binding post ll.

Current is supplied to the switch through a suitable twin-wire conductor cord 5?, which is adapted to pass through an upper metallic shell 58 and comprises a pair of insulated wires 59 and 60 which are connected to the two binding posts 41 and 56, respectively.

The stationary contact 44 is provided with an integral inwardly-extending resilient tongue 6| forming the central contact of the socket, said tongue 6i being adapted to cooperate with the center terminal of a lamp Slot or other current consuming or conveying device wln'ch may be driven into the screw shell 52a.

The stationary contact 44 is connected to the tongue El by a depending integral strip 92 passing through an aperture 53 in the base I0, said strip 62 being attached to the underside of said base It) by a screw 6 and nut I55. The tongue 6| is adapted to be pressed upwardly against the bottom surface of the insulating base It by the lamp 6| a and is shielded against flashingover upon the upper inturned part 66 of the screw shell 52a by a downwardly-extending U- shaped rib 6i formed integral with said base It and surrounding the sides of said tongue IN.

3'! and 38 when the iii) ' Operation In operation, assuming the switch to be in the closed position, when the switch-actuating bead chain 24 is pulled, the rotary carrier 22 will rise on the inclined stationary contact members 43 and 44 in the sockets 42 of the base ll, causing the two extremities 31 and 38 of the movable contact 36 to ride off the upper ends of the stationary contacts 43 and 44. The compressive force of the spring I! will then come into action, causing the carrier 22 to snap down suddenly, bringing the movable contact extremities 31 and 38 into the inclined sockets 4|. The shoulders 39 and 40 will then lie in abutment with each other and the rim of the carrier 22 will lie flat upon the upper surface of the base N. All open spaces will thus be filled, causing any arcs which may have started to flow between the contacts, to be instantly lengthened, cooled and extinguished.

When the chain is released, the ratchet 2| will be restored by the torsional action of the spring I! to its initial position, ready for again snapping on the switch.

One advantage of the, present invention lies in the fact that when the tension in the chain 24 is released, there is no danger of having the same come into contact with live parts of the switch, because all such parts are completely enclosed by insulating barriers as described above.

While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. In an electric switch of the rotary type, an insulating stationary base having an annular depressed groove formed in the face thereof, a plurality of abrupt shouldered inclined recesses in said groove, stationary contact members arranged in alternate recesses, a rotatable contactor member having inclined arms to intermittently pass over said stationary contact members, an insulating carrier for supporting said contactor member and having telescoping relationship with said base, said carrier having a plurality of abrupt shouldered inclined cams adapted to support said arms and fit against said recesses, said carrier having a rim outside of said cams for engaging the surface of said base in overlapping relationship, and means for rotating said carrier, the telescoping arrangement of said carrier and base and the interfitting of said cams in said recesses serving to obliterate the open air space and prevent the formation of arcs.

2. In an electric switch of the rotary type, an insulating stationary base having an annular depressed groove formed in the face thereof, a plurality of abrupt shouldered inclined recesses in said groove, stationary contact members arranged in alternate recesses, a rotatable contactor member having inclined arms to intermittently pass over said stationary contact members, an insulating carrier for supporting said contactor member and having telescoping relationship with said base, said carrier having a plurality of abrupt shouldered inclined cams adapted to support said arms and fit against said recesses, said carrier having a depending annular flange forming a barrier to prevent arcing between the central part of said rotatable contact member and said stationary contacts, and means for rotating said carrier, the telescoping arrangement of said carrier and base and the interfitting of said cams in said recesses serving to obliterate the open air space and prevent the formation of arcs.

3. In an electric switch of the rotary type, an insulating stationary base having an annular depressed groove formed in the upper face thereof, the base of said groove having a plurality of ratchet depressions, stationary contacts seated in alternate depressions, an insulating rotary carrier member having a plurality of depending abrupt shouldered cams shaped to fit said ratchet depressions, said carrier having a rim extending outwardly beyond said cams for engaging the surface of said base, a bridging member having a pair of contact arms supported on the cams of said carrier, and means depending from said carrier inside of said cams for interposing an arc barrier between said movable and stationary contacts.

4. In an electric switch of the rotary type, an insulating stationary base having an annular depressed groove formed in the upper face thereof, the base of said groove having a plurality of ratchet depressions, stationary contacts seated in alternate depressions, an insulating rotary carrier member having a plurality of depending abrupt shouldered cams shaped to fit said ratchet :2

depressions, said carrier having a rim extending outwardly beyond said cams for engaging the surface of said base, and completely covering said groove, a bridging member having a pair of contact arms supported on the cams of said carrier, and means depending from said carrier inside of said cams for interposing an arc barrier between said movable and stationary contacts.

5. In an electric switch of the rotary type, an insulating stationary base having an annular depressed groove formed in the upper face thereof, the base of said groove having a plurality of inclined ratchet depressions, stationary contacts seated in alternate depressions, an insulating rotary carrier member having a plurality of depending abrupt shouldered inclined cams shaped to fit said ratchet depressions, said carrier having a rim extending outwardly beyond said cams for engaging the surface of said base, a bridging member having a pair of contact arms supported on the cams of said carrier, and means depending from said carrier inside of said cams for interposing an arc barrier between said movable and stationary contacts.

6. In an electric switch of the rotary type, an insulating stationary base having an annular depressed groove formed in the upper face thereof, the base of said groove having a plurality of ratchet depressions, stationary contacts seated in alternate depressions, an insulating rotary carrier member having a plurality of depending abrupt shouldered cams shaped to fit said ratchet depressions, said carrier having a rim extending outwardly beyond said cams for engaging the surface of said base, a bridging member having a pair of contact arms supported on the cams of said carrier, means depending from said carrier inside of said cams for interposing an arc barrier between said movable and stationary contacts, and a ratchet member having toothed engagement with said carrier for rotating the same.

7. In an electric switch for a light socket, an insulating base having a centrally depressed annular recess, the base of said recess having a plurality of inclined cams located therein, said cams having abrupt shoulders, stationary contacts resting on alternate cams, a rotatably insulating carrier having face engagement on its periphery with the rim of said annular recess, said carrier having cam projections having abrupt shoulders projecting down into said annular recess, contact members on alternate cam projections for cooperating with said stationary base contacts, and ratchet means connected to said carrier for operating the same. I

8. In an electric switch of the rotary type, an insulating stationary base having an annular de pressed groove formed in the upper face thereof, the base of said groove having a plurality of ratchet depressions, stationary contacts seated in alternate depressions, an insulating rotary down.- wardly spring-'pressed carrier member having a plurality of depending abrupt shouldered cams shaped to fit said ratchet depressions, said carrier having a rim extending outwardly beyond said cams for engaging the surface of said base, a bridging member having a pair of contact arms supported on the cams of said carrier, and means depending from said carrier inside of said cams for interposing an arc barrier between said movable and stationary contacts.

9. In an electric pull chain socket switch, an insulating base having a plurality of inclined cam recesses formed therein, alternate recesses being provided with stationary contact members, a rotary contact member having a pair of connected inclined contact extremities adapted to bridge said stationary contact members, and an insulating carrier ior indexing said rotary contact member, said carrier having a rim located in flat surface engag m nt with said base- 10; In an electric pull chain socket switch, an insulatin ase having a plurality o sp d. sh uldered circumferential cam depressions formed therein, said depressions having end shoulders, inclined contact members being arranged in alternate depressions of said base, a rotary contact member having a pair f c nne ed in lined. contact extremities adapted to intermittently engage said stationary contact members, and an insulat ing carrier for said rotary contact member telescoping with said base having shoulders for engaging the shoulders of said depressions to obliterate the air space and form barriers for preventing the formation of arcs, said carrier having a rim for engaging the surface of said base.

11, In an electric switch, a rotary contact memher havin a pair of connected inclined contact terminals, an insulating carrier having a pair of inclined shouldered backing-up cam lugs for supporting said terminals, and insulating base member havin a plurality of spaced inclined shouldered recesses, stationary contacts located in al-. ternate recesses of said base member for cooperating withsaid rotary terminals, means for indexing'said carrier, and spring means for forcing said carrier into telescoping eng gement with said ba member When the switch is in fully opened Or fully closed position to prevent arcing, said carrier having a pair of depending curved ribs located inside of said backing-up lugs to form additional barriers against arcing.

HARMON. J. COOK. 

